The Robert Runyon Photograph Collection of the South Texas Border Area, a collection of 8,241 items, is a unique visual resource documenting the Lower Rio Grande Valley during the early 1900s. Donated by the Runyon family to the Briscoe Center for American History in 1986, it includes glass negatives, lantern slides, nitrate negatives, prints, and postcards, representing the life's work of commercial photographer Robert Runyon (1881-1968), a longtime resident of South Texas. His photographs document the history and development of South Texas and the border, including the Mexican Revolution, the U.S. military presence at Ft. Brown and along the border prior to and during World War I, and the growth and development of the Rio Grande Valley.

Runyon's first images recorded urban life in Brownsville and the Rio Grande terrain. Then, during the summer and fall of 1913, he turned his attention to political events in Mexico as the Mexican Revolution reached the Texas border. Although small in number, Runyon's images of the Mexican Revolution have great historical significance. The conflict between Rebels and Federals in Northeastern Mexico and into Texas has gone largely undocumented; his photographs provide a unique record of this important event.

As the Revolution intensified, the United States responded by activating Ft. Brown and transferring soldiers from across the country to the Brownsville camp. Runyon minutely recorded this military build-up and the subsequent preparations for U.S. entry into World War I. His photographs show the transition from animal to mechanical power that occurred during this time period as well as the soldiers' camp life and leisure activities.

Runyon returned to familiar subjects after the tumultuous decade of the 1910s. He continued to document city life in the Lower Rio Grande Valley, and he took many photographs of local beaches, lakes, and, especially, the Rio Grande River. Runyon's most profitable enterprise during the early 1920s was studio photography. In addition to studio work, he photographed school groups, sports teams, and the numerous excursion groups which came to Brownsville in the early 1920s as potential participants in the Valley land boom.